Revert "ACPI / video: change acpi-video brightness_switch_enabled default to 0"

This reverts commit 886129a8eebeb (ACPI / video: change acpi-video
brightness_switch_enabled default to 0) as it is reported to cause
problems to happen.

Fixes: 886129a8eebeb (ACPI / video: change acpi-video brightness_switch_enabled default to 0)
Reported by: Bjørn Mork <bjorn@mork.no>
Merge branch 'acpi-video'

* acpi-video:
  Revert "ACPI / video: change acpi-video brightness_switch_enabled default to 0"